Process of treating lumber.



R. L. GILLIAM. PROCESS OF TREATING LUMBER. APPLICATION FILED AUG. 2, 1912.

L@84,266. Patented Jan. 13, 1914.

3140a mfoz jfoberdl z'llialrz I ITE ROBERT In. GILLIAM, OF NEW YORK, N. Y.

rnooEss or TREATING LUMBER).

Specification of Letters Patent.

Patented J an.13,1914.

Application filed August 2, 1912. serial 1%. 712,891.

To all whom it may concern:

Be itknown that I, ROBERT L. GILLIAM, a citizen of the United States, residing at New York, borough of Manhattan, in the county of New York and State of New York, have invented a certain new and useful Improvement in Processes of Treating Lumber, of which the following is a specification.

Because of its hardness and reddish color lumber manufactured from the heart of the American sweet gum tree has 'a much higher market value than that produced from the outer whitish or sap art of the log. The freshly sawed sap lumber from such logs, when exposed to the atmosphere, in the ordinary process of curing, seasoning and dry ing often times takes on in spots or streaks a blackor grayish hue giving it an objectionable appearance or an appearance of incipient decay, thereby adversely affecting its commercial value. I have discovered that with the process or treatment substantially as hereinafter set forth the sap wood of the sweet gum treecan be given a uniform color throughout greatly resembling in appearance that made from the heart of the log or the wood of the mahogany tree.

In carrying out my process I employ a treating chamber or kiln constructed substantially as hereinafter described and on the principle illustrated on the accompanyingdrawings in which Figure l is a view in vertical section. Fig. 2 is a horizontal section of the kiln on the line :rw looking down. Fig. 3 is a vertical section on the line 31-y Fig. 1 on a larger scale to show a detail.

In the views 5 designates a room or chamher, which is constructed so as to be reasonably steam tight and to have a suitable opening at5 through which the lumber is passed into and out of the chamber.

6 is a basin, said basin being conveniently formed of concrete.

7 are horizontally arranged steam conducting pipes of iron arranged within the room and connected witha header 8 at the outer side of the structure. Each of the pipes is provided with a cut-off valve 9 as is also the header at 10. The pipes 7 are perforated as shown at 7 along their upper sides to afford exits for the steam into the chamber, and said pipes are also perforated along their lower sides as shown at 7 to send slanting jets of steam toward the basin to agitate the sap that collects there. The lumber can be carried on a car also of iron into the chamber for treatment, said lumber being sticked or piled on the car so as to leave free spaces between it through which steam can circulate about the lumber.

12 is artock for draining the basin when necessary.

In carrying out my process the lumber, green from the saw, is put into the chamber. Steam is then admitted through pipes 7 to the chamber to maintain the temperature therein at about two hundred and twelve degrees Fahrenheit for a period of say forty eight hours or more, according to the thickness of the lumber treated and the shade desired. From my tests and observation I have found that the slabs or planks of wood one inch thick are substantially deprived of their sap or exudate in about twelve hours.

This sap or exudate collects in the basin at the bottom ofthe chamber where it is retained and utilized for the coloring treatment. I am convinced that it is the presence of the sap or exudate and the iron parts in the chamber which together probably form a compound that causes the coloring of the wood. The introduction of steam is continued after the sap is removed, for say twenty four hours or more according to the thickness of the wood or until the wood has attained the shade or depth of color desired. I have found that with this treatment a satisfactory color of the lumber can be obtained for one inch planks in about forty eight hours. With this treatment the natural variegated whitest sap wood of the sweet gum tree is changed to a uniform rich pinkish hue throughout, resembling the wood of the mahogany tree.

The iron may be supplied in a different way as for example in the form of filings or shavings and the quantity thereof regulated, and this is especially desirable or necessary if or after the iron originally in the chamber becomes so far coated as to render it incapable of supplying the coloring element. Or the iron may be introduced into the chamber in a prepared or compound state, and in my claims where I specify iron I do not intend to confine myself to iron in the pure or simple or uncompounded state.

What I claim is:

1. The process of modifying the color of the sap wood of the sweet gum tree consisting in subjecting the wood in a confining chamber to the action of steam until its sap has been substantially removed and continuing said action in the presence of wood sap and iron until the desired shade of color has been obtained.

2. The process of modifying the color of the sap wood of the sweet gum tree consisting in subjecting the wood in a confining chamber to the action of steam after its sap has been substantially removed and in the presence of such sap and iron.

3.' The process of modifying the color of the sap wood of the sweet gum tree consisting in subjecting the wood in a confining chamber to the action of steam at a temperature approximating 212 degrees Fahrenheit and continuing such action beyond the time when the sap is substantially removed and in the presence of the sa and iron.

4. The process of mo ifying the color of sap wood of the sweet'gum tree consisting in subjecting the wood in a confining chamber to the action of steam in the presence of exudate of wood and iron.

5. The process of imparting a pinkish color to the sa' wood of the sweet gum tree consisting in t e subjecting the wood in a confining chamber to the action of steam until the sap is substantially removed, and continuing such action thereafter in the presence of such sap and iron until the desired shade of pink is obtained.

6. The process of modifying the color of i the sap wood of the sweet gum tree consisting in subjecting the wood in a confining chamber to the action of steam and continuing such action beyond the time when the sap is substantially removed in the presence of iron in a form adapted to modify the color of the wood.

ROBERT L. GILLIAM.

Witnesses RICHARD E. Jones, MARY Gr. MULLEN. 

